1. Field of the Description
The present invention relates, in general, to projection techniques and projectors, and, more particularly, to an assembly or system for splitting and/or distributing illumination, such as high power illumination including illumination, light, or output of a laser engine or laser light source, to one-to-many projectors and/or to other illumination output devices (or illumination-using devices).
2. Relevant Background
Projectors and similar illumination/light output devices are used in many settings to create entertaining displays in theaters, amusement parks, and other environments. Over the years, there has been a continued demand for brighter and more efficient light sources for projectors, and projector light source technology has seen many changes in recent years. From improvements to the traditional projector lamp to the introduction of lasers as light sources, the newest projector light sources are more efficient and longer lasting than prior projector light sources.
The majority of existing projectors use lamps as a light source, but it has proven difficult to meet demands for higher luminance or higher power projectors with these light sources. Xenon arc lamps may be used as a “high” luminance or power light source, but even these lamps are often too dim and are often not very long lived, which can increase maintenance requirements. More recently, projectors have been designed and distributed that utilize laser light sources, e.g., blue laser phosphor models of laser light sources (or, more simply, laser sources). These projector light sources are desirable as they can provide high power (or luminance), e.g., thousands of lumens with some laser projectors being rated at 6000 lumens, and laser sources for projectors are durable and long lasting (e.g., tens of thousands of hours of use).
With these improvements in mind, the cinematic projection industry is moving towards laser projection to achieve higher screen luminance. In part, the move to laser sources for projectors is driven by the need to compensate for the brightness reduction observed when projecting time-multiplexed or polarization-based stereographic three-dimensional (3D) movies. Laser sources and digital projection are desirable to provide images with larger dynamic range, greater color gamut, and higher frame rates. When compared with conventional lamps (such as xenon lamps), laser sources are also more efficient, are more consistent in output, and have longer life spans.
While laser sources are capable of producing extremely bright illumination, laser sources are typically very expensive when compared with traditional projector light sources. To address the cost issue, there has recently been a move toward using a centralized laser source and dividing its output between multiple optical fibers for delivery to wavelength converters (e.g., infrared (IR) to visible color) and projector heads. This arrangement is sometimes referred to as “a light farm.” The light farm may have racks of lasers with an efficient power system and central cooling. Light is distributed to one or several projector heads. Each projector head may also still need cooling, but such cooling fans can be smaller and be quieter than the fans used to cool the remote laser(s) and than projectors with integrated light sources, which is desirable in many projection settings where the projector may be near the viewing audience. The projector heads may be smaller than projection units with integrated light sources and may be mounted in the viewing room eliminating the need for a separate projection room.
Demonstrations and sales of cinema laser projectors have already occurred and installations will likely gain momentum in the near future as new laser sources and projectors become available. In initial systems for theme parks and other settings, laser projection will likely be provided by a retrofit of existing xenon lamp projectors, and, as a result, these systems will not experience the benefits of a centralized light farm. As new theaters and attractions are built or refurbished, light farms likely will be incorporated into the designs. However, the fiber network topology or layout and light splitting and distribution will likely be concurrently designed and will be static, e.g., the splitting of outputs from a centralized laser will be defined at the time of building or refurbishing the theater or attraction.